Seat for buses

Abstract: They improve the passenger's passive safety and comfort. They are comprised of a deformable frame to absorb the energy transmitted in the presence of an impact, without any portion of the same becoming detached. The design thereof has no sharp angles or edges and in the back there are perfectly inserted accessories. The footrest is also hidden without projecting, having blunt forms. The frame has two crossbars (6) secured to the side feet (4.) The chassis or bed of the seat is formed by two triangular side plates (8, 9) braced by two cylindrical bars (13) passing through cross members (7) welded to the crossbars (6.) The back (3) is hinged to the top angular area of these plates (8, 9) and is adjustable as its frame (12) has an extension (17) connected to an adjustment mechanism (19) with an automatic instant blocking system. Optionally, the seat on the aisle is shiftable. The headrest is cushioned in the back since the rear frame remains lower. In this frame (38) a glass holder (46), an ashtray (43), a handle (45) and a hanger (44), and optionally a novel adjustable mirror, remain inlaid.

Description: The present specification refers to a seat structure for buses and the like, which provide some advantageous and relevant features with regard to presently used seat structures. In broad outline, the seats that are presently used in buses and the like, though they provide functional features common to the seat in question, they nevertheless have certain deficiencies. EP-A-0 383 955 discloses a prior art seat structure for buses and the like, according to the preamble of claim 1 of the present application. Further prior art seat structures for public transport vehicles are known from EP-A-0 330 594 and EP-A-0 336 852. As to the frame or chassis in which the normally two seats are supported and secured, the way and means with which this anchoring is done in some prior art structures, are not totally satisfactory because they are open and in a collision even at an average speed, they can previously come loose or after the chasis has been deformed, which implies a high risk for the passenger's safety. According to the invention, a seat structure is given which has the features as set forth in claim 1. Further features of the seat structure are given in the dependent claims. In the first place, as a novel and advantageous feature we can cite the fact that the frame or chassis in which the double seats are rigidly supported, is defined by two crossbars rigidly fastened to some side legs solid to the floor, carrying out the interconnection with the frames of the seats, upon the frames having some bars that pass through holes provided in the cross members welded to the crossbars of the frame, which prevents these parts from coming loose from the whole, as we have set forth above. This way of inserting the seats themselves in the frame makes it possible to also optionally, easily and safely achieve, at the factory, that the seat on the aisle side can shift a short distance away from the other seat. Thus when the passengers consider it to be convenient, they can separate their seats for their comfort. The frame of the back is provided with welded half shafts for rotation thereof in the holes provided in the side plates that are solid to the frame of the respective seat The frame of the back portion is materialized by a reverse U-shaped frame whose branches have deviations to obtain an ergonomic shape of the back. One of these branches of the frame has a descending extension for hinged connection to the mechanism that adjusts the inclination of the seat, this mechanism being very effective and capable of blocking the chosen angular position in any point of its angular stroke. This mechanism noticeably improves the complex structure that present mechanisms have for an efficient functioning, not having those pieces that can have the risk of breaking or deforming during normal functioning thereof as well as in the face of an unexpected impact. To this regard we can also say that the seat on the whole can last for an unlimited amount of time and does not require maintenance of all the functional devices, including the one we are now referring to. The adjustment mechanism has a threaded shaft, one of whose ends remains anchored, by means of a support or fork, in the extension of the frame of the back. This threaded shaft, or stud passes through a fixed piece or head of the mechanism, that remains anchored, or connected to the frame of the seat, there being a coaxial spring surrounding the stud, in the area between this head and the end hinging to the back. The moveable piece or head has in the recess for the passing of the stud, a wall obtained by the mechanizing of two holes slightly deviated angularly, one of them being smooth to permit axial movement of the threaded stud, while the other one, which breaks with the anterior one in a central point, is threaded with the same pitch and diameter as the stud. Depending on the tilt position (only movement that the head can make upon actuating upon a control solid to it), axial movement of the stud is permitted to coincide with the smooth hole, or else, the whole is blocked upon the threaded surfaces of both elements coinciding, as a toothed interconnection. It has been provided for that the stress of the helical spring is applied upon a point eccentric to the geometric axis of the threaded rod, in the head of the mechanism, precisely on the edge of a milling that the same has, thus forcing the stress itself of the spring to determine the formation of a pair of forces that force the head to take on the locking position, whereby in order to come out of this condition it is necessary to actuate the control of the same so that it turns. Upon canceling the action upon the control lever and once the back has been positioned with the required inclination, upon releasing the control lever the locking position is automatically recovered. As to the footrest structure, as well as to the positions that it is capable of occupying, in order to remain ready for use, or else, drawn back by rotation upon the seat, without being an obstacle, we can say that it is hinged to both supports solid to the tubular crossbar of the frame for support and connection of the seats themselves. It is aided by a spring and has a useful surface for resting one's feet, notably rounded to eliminate vertical edges thereof, as well as to offer the rest of the surface thereof with a blunt contour, also remaining duly inlaid in the housing provided for in the rear part, as we have indicated above. To contribute to the passenger's passive safety, in the rear the back has a frame that ends before reaching the headrest area, therefore it has a top elastic area in the event of a possible impact. It ends a little more after rising above a horizontal strip inlaid and divided into compartments to house in each one of them the accessories or attachments that normally exist on this type of seat. In one of them there is a collapsible ashtray; a glass holder preferably remains located in the center one which upon being extended by collapsing, a support surface is provided and another one higher up as a guardrail; in another compartment there is a tension piece occupying a diagonal position, used as a handle. In this last compartment mentioned there is also an ascending appendix that can be used as a hanger. None of these accessories projects beyond the frame, in the non-use or "folded" position. It has also been provided for that an adjustable mirror can be advantageously assembled in the center compartment thus the mirror can be put in the place most convenient for the passenger, without taking into account the angular position the back is in, hence let us remember that the mirror is to be used by the person sitting in the seat behind. Thus it can be independent of the angulation that the back has, chosen by the passenger sitting in the seat whose mirror is being moved. As a special characteristic of this mirror, we can say that the surface that reflects the image, can be adhered, or preferably, achieved by surface treatment of the adjustable body. To prevent it from being forced by an inept person, or even a destructive one, the body of the mirror has a side wall that extends orthogonally by the sides and bottom edge, with a shape that occupies a generally prismatic-triangular volume, so that the bottom wall is curved, thus closing access to the rear part of the front surface thereof, for any position it occupies, limited angularly by both stops. In order to provide a better understanding of the features of the invention and forming an integral part of this specification, some sheets of drawings in whose figures with an illustrative and non-restrictive manner the following has been represented, are attached hereto: Figure 1 is a raised side view of a seat for buses and the like, including the improvements object of the invention. Figure 2 is a raised side view of figure 1, showing the rear part of the seat, not including the support frame and with a single seat in a two seat area. Figure 3 is a partial sectional raised side view of the hinging area of the back and the seat itself. Figure 4 is a partial raised side view of the front part of the seat, specifically to complete the left-side area of figure 3. Figure 5 is a raised side view of the bed or frame of the seat portion. Figure 6 is a plan view of the two seat bed as a whole. Figure 7 is a raised view of the seat back frame as a whole. Figure 8 is a raised side view of what is shown in figure 7. Figures 9 and 10 are respective views of the locking device for setting the position of the back, in the lock position and release position, respectively, figure 10 being only a partial view. Figure 11 is a partial raised side view of the seat showing precisely the area where the footrest is located. Figure 12 is a raised side view of that which is shown in figure 11, showing the anchoring of the footrest. Figure 13 is a raised rear view exclusively of the footrest element, in a folded position. Figure 14 is a raised side view of the seat, showing the top portion of the back of the same. This figure is complemented at the top by that which is shown in figure 3. Figure 15 is a section along the A-A cutting line of figure 14. Figure 16 is a section along the B-B cutting line of figure 2. Figure 17 is a section along the C-C cutting line of figure 16. Figure 18 is a section along the D-D cutting line of figure 2. Figure 19 is a section along the E-E cutting line of figure 18. Figure 20 is a section along the F-F cutting line of figure 2. Figure 21 is a front raised view of the adjustable mirror insertable in the center rear area of the back. Figure 22 is a section along the G-G cutting line of figure 21. Referring to the numbering used in the figures, we can see how the improvements introduced in seats for buses and the like, which the invention proposes, have in this preferred embodiment, the essential features that we are going to specify in detail hereinafter. Reference (1) designates the frame or chassis in which the two seats themselves (2) as a whole are supported. The backs (3) are hinged in top points of the side plates of the bed or frame of the seat (2), as we will see later on. Frame (1) includes the feet or side surfaces (4) that are secured to the floor of the bus and raise the bed (5) (see figure 6) that fastens the seats. The fastening is done by means of screws passing through the pair of holes selected from the crossbars (6.) The crossbars (6) are tubular and have a rectangular section and they are also braced by cross memebers (7) (see also figures 3 and 4.) To the left of figure 6, we can see how the crossbars (6) remain welded to the side plate (7) whose geometry can be seen in figure 5. These crossbars (6) are also welded to one of the center plates (9), these plates (8) and (9) being the ones that comprise the sides of the seat portion placed on this side. The center side plate (9) is very similar to the end side plate (8) since it only differs in that it has some cuttings for adaptation and welding thereof to the crossbars (6), It is noteworthy that these side plates (8) and (9) include in the top angle of the general triangular shape a hole (10) for fitting in the bushings (11) welded to the frame (12) of the frame of the back (3), as we can see in figures 7 and 8, materializing the hinge pin of the back with regard to the seat. Continuing with figure 6, we can see that to the right of the same the structure of the bed is shown to permit side movement of the seat on the aisle, this assembly being optional as we have said above. The frame of this seat is formed by the side plates (8) and (9) which in this case are naturally not welded to the crossbars (6) of the bed, but rather they are only connected by the cylindrical bars (13) whose ends are threaded to receive the nuts (14) (see also figure 5.) The bars (13) pass through the bearings (15) incorporated in the cross members (7), therefore it is easily inferred that this frame can be moved to the right of figure 6 until the side plate (9) knocks against the bearings (15.) The limit positions are ensured with the help of the tension piece (16) that hinges in the side plate (8) and that locks in the cross member itself (7.) They are provided with the respective fastening notches. It is understood that the seat located next to the window remains stationary upon having the sides plates (8) and (9) of its frame welded to the crossbars (6) of the bed. The seat on the aisle would be also mounted in this way when this functional use were not included. Now making special reference to figures 7 and 8, we can see how the frame (12) of the back (3) of the seat has a reverse U shape, one of its branches extending to define the arm of lever (17) provided with end hole (18) for hinged connection to the mechanism adjusting the inclination of the back (3), generally referred to as number (19) and whose functional structure we can see in figures 9 and 10. The cited adjustment mechanism (19) is comprised of a threaded rod (20) that ends in the connecting fork (21) hinged to the arm of lever (17) of the frame (12) of the back (3.) The control head (22), which remains located in a fixed point of the chassis of the seat (2) remains located on the threaded rod (20), having only oscillating or tilting movement around a shaft passing through the center point of the discoidal shape that it has, this movement being achieved upon having a shaft to which the operating control (23) is solid to (see figure 1), it being possible to tilt from the position shown in figure 9, to the position of figure 10 and vice versa. The head (22) is provided with a pair of diametric holes (24) and (25), whose geometric axes form together a small angle α. Hole (24) is smooth and has a diameter slightly larger than that of the threaded rod (20) thus when this hole (24) is aligned with said rod (20), axial movement of the rod (20) can take place, in favor or against the spring (26) that coaxially surrounds it and that remains laid between bushings (27) that easily slide. The other diametric hole (25) is threaded with the same pitch and diameter as the threaded rod (20), therefore when the head (22) is in the position shown in figure 10, the locking position for the back is achieved since the helicoidal section of the threaded shaft (20) fits with the threaded locking surface of the head (22), since the threaded hole (25) coincides with the threaded rod 20. Thanks to the existence of the flat milling (28) of the discoidal head (22) that eliminates a segmented portion of the same, the pressure transmitted by the helicoidal spring (26) determines that the head (22) is automatically positioned under pressure, to block the mechanism, in other words, acquiring the position of figure 9. A turning torque in the direction of arrow (29) is formed. When one desires to change the position of the back of the seat, it is necessary to actuate the control (23) (figure 1) so that the head (22) acquires the position shown in figure 10, the studs that define the threaded portions of the hole (25) become unlocked from the helicoidal thread of the threaded rod 20. When the passenger presses his back against the back (3) of the seat, or else progressively releases the pressure to prevent a sudden thrust of the same, the desired reclined position can be sought, and upon releasing the actuating lever of this mechanism rotation of the head (22) in the locking direction will be automatically achieved by the elastic stress of the helicoidal spring (26) that applies its stress in the bottom edge of the milling (28), off center with regard to the geometric axis of the threaded rod 20. The nuts (30) and (31) show the bottom of stroke stops, which are adjustable in order to previously set the positions of maximum and minimum angulation for the back. In figures 11 to 13 we can see the footrest (32) represented. With the discontinuous dash line we can see the position of use, while the continuous line shows the collapsed position so that it does not imply an obstacle for the passenger when he tries to get out of his seat. Reference (33) designates the hinging support of the footrest (32), solid to the crossbar (6) of the bed, having the shape of a fork between whose branches it is hinged. By means of spring (34) which fits with the footrest (32), the collapsed position is recovered in order to remain lodged in the rear top recess (35) of the seat (2), so that it is not an obstacle for the passenger, there being a small buffer 36. We see that the useful surface of the footrest, referred to as 37 for resting one's feet, has a design without any sharp angles or edges, for the purpose of improving the passenger's passive safety, a purpose which the invention seeks at all times. In figures 14 to 20 we can see how the frame (38) of the seat (3) has in the top area the generally rectangular and oblong recess, referred to as (39) , divided into three compartments (40, 41 and 42), in this preferred embodiment. In figure 2 we can see a rear raised view of the accessories included in these compartments. In compartment (40) a collapsible ashtray (43) is mounted. In figures 16 to 19 we can see different plan and raised sections of this ashtray (43) in order to see its geometry and way in which its collapsing and locking are carried out. Figure 20 shows a section by the cutting line F-F of figure 2, specifically of compartment 42 which is to house the hanger 44 and handle 45. In figure 15 we can see the horizontal section of this handle and hanger compartment. The center compartment (41) where the glass holder (46) is contained has a geometry which we can see in figures 14 and 15, as well as in the rear view shown in figure 2. In the center compartment (41) of the general recess (39) of the frame (38) of the back, as we have said above, an adjustable mirror, in replacement of the glass holder (46) can be mounted. The geometry of design of the adjustable mirror, as well as its mounting in this compartment (41) can be seen in figures 21 and 22. The body of the mirror is referred to as number (47) and it can turn around the half shafts (48) that emerge from the side walls (49) in which the front surface (50) of the body of the mirror (47) extends, precisely where there is a pair of grooves that give rise to the formation of a tongue (51) to achieve the flexibility needed to insert the half shafts or lugs (48) in the holes (52) previously made in the side walls of compartment (41.) The side walls (49) also extend at the bottom part, though in this case with a curved shape and with the curvature center precisely in the rotation axis 48. In this figure 22 we can see the two orientation limit positions of the mirror, with the continuous line being the collapsed position so that no obstacle with regard to the general surface of the frame (38) is implied and with the chain line the position of maximum angulation, precisely upon knocking against the top edge of the front surface (50), in the bottom of the compartment (41.) The continuous line is obtained upon the sides (49) knocking against the end of the grooves (53) that permit the introduction of the bottom triangular projections of the sides, this groove continuing at the bottom part in order to also permit the passing of the bottom arched wall, advantageously provided with a stop shoulder. The front surface of the mirror thus remains closed by all of its sides, whatever the angular position of the mirror is, since when the same is in the maximum angulation position, the inside edge of the bottom arched wall is still hiden in compartment 41. Reference 54 designates the elastic strip used as a bag.

Claims: A seat structure for buses and the like, said seat structure comprising: at least two side feet (4), two seats (2), two back supports (3), and a frame (1) in which the seats (2) are mounted, whereby said frame (1) includes two parallel tubular crossbars (6) secured to said side feet (4); characterized in that the frame (1) further comprises: at least two cross members (7) which are substantially orthogonal to said crossbars (6) and which are welded to said crossbars (6) such that they interconnect said crossbars (6), each of said cross members (7) being provided with a plurality of holes; at least two cylindrical bars (13) disposed substantially parallel with respect to said crossbars (6), said cylindrical bars (13) passing through respective ones of said holes in said cross members (7); four vertical side plates (8,9), each side plate (8,9) having a substantially triangular contour, two first ones of said side plates (8,9) being fixed to said crossbars (6), two second ones of said side plates (8,9) being fixed to said cylindrical bars (13) at points close to the bases of said side plates (8,9), each of said four side plates (8,9) having an upper vertex in the vicinity, of which there is a hole (10) for hinged connection of a frame (12) of the corresponding back support (3); whereby the seat structure further includes armrests which are pivotably connected to corresponding ones of said side plates (8,9), the armrests being pivotable in a vertical plane; and the frame (12) of the back support (3) further includes a descending extension (17) provided with a end hole (18) for hinged connection to a mechanism (19) for adjusting the inclination of the back support (3). A seat structure according to claim 1, wherein the structure includes footrests (32), each footrest being pivotably hinged to supports (33) which are fixed to a rear one of said tubular crossbars (6), the footrest being pivotable to a collapsed position in which the footrest, aided by a spring, is situated upwards and remains housed in a rear recess (35) provided in the seat structure, in order not to be an obstacle for a passenger sitting in a seat behind. A seat structure according to any of the preceding claims, wherein the seat (2) situated between the two second ones of the side plates (8,9) is laterally displaceable by means of the cylindrical bars (13) being movable through the holes or bearings (15) of the cross members (7), said seat (2) being secured in its limit positions by means of a tension piece (16) hinged to an outer one (8) of the side plates of the seat and interconnectable with the cross member (7) which is closest to said tension piece (16). A seat structure according to any of the preceding claims, wherein the mechanism (19) for adjusting the inclination of the back support (3) comprises a threaded rod (20) having a first end which ends in a connection fork (21) hinged to the descending extension (17) of the frame (12) of the back support, said threaded rod (20) being inserted in a head (22) provided with a first hole (24) and a second hole (25) passing through said head and forming a small angle (α), the first hole (24) being smooth and with a diameter corresponding to the threaded rod (20), whereas the second hole (25) is threaded at an equal pitch as the rod (20) and has a diameter corresponding to the threaded rod (20), whereby the head can be turned to an angular position wherein the first hole (24) is aligned with the rod (20) such that the the threaded rod can vary the inclination of the back support (3), and the head can be turned to a position aligned with the rod (20) in which the second hole (25) is aligned with the rod (20) thereby producing a locking of the rod (20) by means of interlocking the threads of the second hole (25) and the threads of the rod (20), a coaxial spring (26) surrounding the rod (20) between the head (22) and the fork (21), this spring exerting a constant thrust against said head (22) by means of a guide bushing (27), the head (22) being provided with an exterior control means for tilting of the same, said control being linked to the frame of the seat structure; the head (22) having a flat surface (28) in correspondence with a front surface of said bushing (27), said flat surface being generally perpendicular to the geometric axis of the second hole (25), thereby assuring that the locking position is maintained automatically as long as the head (22) is not made to tilt in order to have the first hole (24) coincide with the rod (20); there being a pair of nuts at the ends of the threaded rod (20) in order to define adjustable stop means to limit the angular movement of the back support (3).

Inventors: SINGLA CASAYAS JUAN, SINGLA CASASAYAS, JUAN
Applicants: FAINSA SA, FABRICACION ASIENTOS VEHICULOS INDUSTRIALES, S.A. (FAINSA)
Application year: 1994
Main classification: B60N2
IPC codes: B60N2